1. Field of the Invention
The present invention relates to connectors, and especially to a modular jack designed to prevent improper insertion of smaller sized plug connector.
2. Description of the Prior Art
RJ-11 and RJ-45 receptacles respectively engaging with RJ-11 and RJ-45 plugs are commonly used in network communications. RJ-45 receptacle and plug have larger dimensions than RJ-11 receptacle and plug. Therefore, an RJ-11 plug or any smaller sized RJ plug may be inadvertently inserted into an RJ-45 receptacle, which may result in damage to the terminals of the RJ-45 receptacle. U.S. Pat. No. 6,186,835 B1 issued to Cheshire on Feb. 13, 2001 disclosed a conventional modular jack. The modular jack comprises an insulative housing and an anti-mismating member integrally formed on a jack entry leading into the jack cavity. The anti-mismating member has a ramp attached to the jack entry. The ramp has an inner movable end with a vertical barrier. An undersized inserted plug is blocked by the vertical barrier. A full-sized inserted plug engages with the ramp, rides along and moves the flexible ramp. The vertical barrier moves out of a stopping position, therefore allowing the full-sized inserted plug to be fully seated in the cavity. However, the anti-mismating member formed is integrally with the insulative housing, which makes manufacturing of the insulative housing complicated. Moreover, the anti-mismating member is made from plastic material and will loose its flexibility after repeated use.
U.S. Pat. No. 6,296,528 B1 issued to Roberts et al on Oct. 2, 2001 disclosed another conventional modular jack. The modular jack comprises an insulative housing defining a plug-receiving cavity and a pair of anti-mismating members received in the insulative housing. Each anti-mismating member comprises a sliding surface and a stop surface attaches to an inner side of the sliding surface at a free end thereof. The stop surface is provided for blocking an undersized plug being inserted. When a mating plug is inserted into the cavity, the leading edge of the mating plug contacts the more forwardly-positioned sliding surface before reaching the stop surface and rides along the sliding surface, which causes the sliding surface to move upwardly. The movement produce a corresponding movement in the anti-mismating member and the stop surface thereon such that the stop surface is located out of a stop position, permitting full insertion of the mating plug into the cavity. However the anti-mismating members are made discretely, more constituent parts produce an incompact frame. Also, similar to the aforementioned U.S. Pat. No. 6,186,835, for forming a relative larger and reinforced stop surface, that anti-mismating member is made of plastic thus resulting in losing flexibility after repeated use. On the other hand, U.S. Pat. No. 6,257,935 discloses the anti-mismating member made of metal for superior flexibility thereof. Anyhow, such anti-mismating member may only provide a thin planar stop surface confronting the undersized plug, thus result in possibly tilting or damage of the anti-mismating member if the plug is improperly severely obliquely inserted into the jack. Thus, it is desired to have a new type anti-mismating member which has not only the superior resilience for enduring repeated use but also the reinforced stop surface for resisting any improperly server oblique insertion of the plug so as not to be damaged.